MagicHat - 20 - Adding wisdom

Thanks to the Text-To_Speech engine, I can easily add a nice function to the MagicHat: the capability to say wisdom phrases while it's idling

The implementation will be based on a web service that provides quotes as a JSON document

I found a lot of alternatives on www.mashape.com and I selected the quotes service provided by quotbook.com

The URL to invoke to get a new quote has the following format

https://yusufnb-quotes-v1.p.mashape.com/widget/~{search}.json

where {search} is the topic you are interested to get a quote about. To stay on the challenge topic, I will randomly search for the following topics

• rowling
• magician
• harry potter

The quote web service will be queried by theNodeJS application

function getQuote(topic) {
  var http = require('http');
  options = { 
    host: 'yusufnb-quotes-v1.p.mashape.com', 
    path: '/widget/~' + topic + '.json',
    port: '1338', 
    headers: {
       'X-Mashape-Key': '<your mashape key>',
       'Accept': 'application/json"

     } }; 
 
 
  callback = function(response) { 
  r str = '';
     response.on('data', function(chunk) { 
      str += chunk; 
    }); 
    response.on('end', function() { 
      console.log(str); 
      var obj = JSON.parse(str);
 
 var mp3url='http://tts-api.com/tts.mp3?q='+encodeURIComponent(obj.quote);
      getMp3(mp3url, filename, function() {
        exec('/usr/bin/madplay -A10 ' + filename);
      });
    }); 
  }
 

  req = http.request(options, callback); 
  req.end();
 };

Since the Arduino side is aware whether the MagicHat is idling or not, the quote function will be triggered by Arduino itself by sending a new command

Serial1.println("QUOTE");

This command will be parsed by the serial port's data handler

// quote topics
var topics = ['rowling', 'magician', 'harry_potter'];

// generate a random int value between low and high (including limits)
function randomInt (low, high) {
    return Math.floor(Math.random() * (high - low) + low);
}

// serial port data handler

yunPort.on('data', function(data) {

  //console.log('data ' + data);
  
  _data = _data + data;
  var eol = _data.indexOf("\r\n");
  if (eol > 0)
  {
    _data = _data.substring(0, eol);
    if (_data.substring(0,5) == "PLAY ")
    {   
      console.log("Received command " + _data.substring(0,5)+","+_data.substring(5));
      var text = _data.substring(5);
      _data = "";

      text = text.replace(/ /g, '_');
      var filename = '/mnt/sda1/' + text + '.mp3';
      console.log("Checking file " + filename);
      if (fs.existsSync(filename))
      {
        console.log("Playing file " + filename);
        exec('/usr/bin/madplay -A10 ' + filename);
      }
      else
      {
        var mp3url='http://tts-api.com/tts.mp3?q='+encodeURIComponent(text);
        getMp3(mp3url, filename, function() {
          exec('/usr/bin/madplay -A10 ' + filename);
        });
      }
    }
    else if (_data.substring(0,5) == "QUOTE")
    {
      getQuote(topics[randomInt(0,topics.length-1)]);   
    }
    else
    {
      if (_ws)
        _ws.send(_data);
      
      _data = "";
    }  
  }
});